[SOLVED] Error installing along side Windows 10

[stevef]

I did not get a choice of which OS to boot.

On a dual boot system, usually one or the other OS will boot by default.  In that case, it is necessary to intervene to select the other OS or change which OS boots by default.

It should be possible to boot from W10 and you should be able to mount a Windows partition when you boot Linux.
But NTFS is proprietary to MS and Windows optimisation like fast boot/fast start can make the disk appear 'unclean' from the Linux point of view.
The mount error message you are seeing implies Linux is seeing the NTFS partition as unclean and won't mount it.
There are some steps that Linux can do to try to work around the problem, but it is usually best to get Windows to leave the disk clean.

To try this you need to get the system to boot from W10.
The best method to do this will depend on your system.
To begin, try to access the UEFI/BIOS settings while turning the system on.
Look for boot manager options and select the option for W10 at next boot.
When you get W10 working, ensure fast startup is disabled.